JMIR Publications

ABSTRACT

Social media exposure is commonly approximated by platform use, frequency, or time spent online, measures that reveal little about the health-related content presented to individuals or the conditions of presentation. Although digital exposome and digital determinants of health frameworks recognize the relevance of digital environments to health, individual-level social media exposure remains difficult to operationalize. We propose the social media exposure event as a candidate epidemiological unit: a discrete occasion on which specific health-related content is presented to an individual through a social media interface or function within its social, algorithmic, commercial, and temporal context. A four-level framework distinguishes platform ecology, delivery, individual-level presentation, and separately assessed responses and outcomes. Relevant event characteristics include content and source attributes, visible social signals, emotional framing, repeated presentation, commercial relationships, and timing relative to health-related decisions. Perceived expertise, emotionally salient narratives, and repeated encounters may shape interpretation, but presentation alone does not establish attention, belief, or action. Allergic disease illustrates potential applications to diagnostic testing, allergen avoidance, dietary decisions, treatment adherence, and psychosocial burden. An example involving food-specific IgG testing on a Chinese social media platform illustrates the limits of inferring individual exposure and health consequences from public posts and comments. The framework is conceptual, not a validated measurement instrument. Future research should establish reliable event definitions, develop ethically acceptable methods to reconstruct individual encounters, and test whether event-level measures add explanatory or predictive value beyond conventional measures of social media use.